Buffing wheel, buffing wheel fabric, and method of treating the fabric



K. H. BARNARD July 3, 1934.

BUFFING WHEEL, BUFFING WHEEL FABRIC, AND METHOD OF TREATING THE FABRIC Filed March 7, 1954 Patented July 3, 1934 UNITED STATES PATENT OFFICE 1,964,901 I, BUFFING WHEEL, BUFFING WHEEL FABRIG,

AND METHOD OF RIC TREATING THE FAB Application March 7,

2 Claims.

This invention relates to bufling wheels, an improved fabric therefor, and a process of preparing the fabric.

A buflingwheel usually consists of a stack or collection ofconcentrically disposed contiguous fabric discs which may be clamped together at the middle portion thereof on a driving arbor with the peripheral portions otherwise free from attachment or the discs may be sewed or otherwise secured together to form a buffing wheel, the peripheral portion of which is sufiiciently loose and flexible to yield under the pressure between it and the part being bufied. The discs preferably, although not necessarily, are composed of a cotton fabric having as nearly as practicable a balanced weave, that is, an approximately equal number of warp and weft strands or yarns of similar size and twist per unit length, with the weaves of the various discs of the wheel being staggered or angularly displaced. The periphery of the wheel carries a polishing material or compound, usually tripoli, which isapplied to the wheel as often as maybe necessary by pressing a soft wax stick or cake containing the tripoli against the periphery of the rotating wheel.

Bufiing wheels are subjected to hard usage. They are run at high speed and subjected to heavy pressures and rotate against irregularly configurated objects, usually of metal. Hence the wheels are subjected to rapid wear and even to charring due to the frictionally developed heat of buffing. A good bufiing wheel should wear uniformly about its periphery without the formation of any flat spots or irregularities. The material should wear off the wheel in the form of fine fibres and not in relatively long threads or ravelings. The wear of the wheel should also be slow so that the wheel has a long life.

It is an object of the present invention to provide an improved bufing wheel having a long life and slow and uniform wear about its active periphery.

A further object is an improved bufiing wheel fabric.

A. further object is an improved process for treating the fabric.

Fig. l. is a plan view of a buffing wheel embodying the present invention.

Fig. 2 is a view similar to Fig. 1 but with the fabric laminations partially cut away to illustrate the staggered arrangement of the weave of the discs.

Fig. 3 is a side elevation of a bufiing wheel on its arbor. I

The bufiing wheel 10 consists of a stack or col- 1934, Serial No. 714,530

lection of concentric contiguous fabric discs 12, the stack or collection having a center hole 14 to receive a driving arbor 16 and the stack of discs being clamped at the center between the flange 18 of the arbor. The discs of the wheel can be otherwise free from interconnection or they can be secured together by any suitably arranged line or lines of stitching 20. The weave of certain discs is staggered with respect to the weave of other discs, as indicated in Fig. 2, so as to distribute the warp and weft strands or yarns uniformly around the circumference of the disc. The buffing wheel as thus constructed is or can be more or less common in the art.

My invention resides in a buffing wheel the fabric of which is treated to improve its resistance to wear and to cause it to wear uniformly.

In accordance with the present invention the fabric, and particularly'a cotton fabric, of which the buffing wheel is composed contains in its yarns materials which impart increased durability thereto and which prevent the fibres from wearing off in long lengths and which also improve the finish of the buffed article. The fabric contains rosin in a form by which it is retained in the yarns against the bufiing operation and centrifugal force and which stiifens and strengthens the yarns and a hygroscopic material which maintains the yarns at a relatively high moisture content and thereby causes them to be of enhanced durability and retains the rosin compound in the wheel. Specifically the rosin is in the form of a rosin soap and the hygroscopic material is glycerin both of which are desirably water soluble.

In the manufacture of the wheel the fabric from which the discs are made is placed in a water solution of the rosin soap and glycerin, the solution preferably containing, by weight, about 10% of rosin soap and 6% of glycerin. Any good commercial rosin soap is satisfactory for my purpose but the rosin soap I use is made by saponifying a mixture of 100 pounds of rosin in 80 pounds of water with 40 pounds of caustic soda solution at a strength of 30 B. This is done by boiling and gives a soap solution which is diluted to 20% in water, the diluted solution containing 10% of rosin soap. The glycerin is added to the diluted solution.- The fabric is saturated with the rosin soap and glycerin solution, surplus solution is then expressed from the saturated fabric by squeezing or otherwise, the fabric is dried and then discs of suitable size are cut from the fabric. Obviously,'however, the discs themselves may be so treated although this is not desirable from a commercial standpoint.

A suitable apparatus for impregnating the fabric and removing surplus solution therefrom may consist of a trough containing the solution through which the fabric is drawn by a pair of squeeze rolls located over the trough which express surplus solution from the saturated fabric. The fabric at this point will contain approximately its own weight of solution so that 100 pounds of fabric will contain approximately 10 pounds of rosin soap and 8 pounds of glycerin. The drying of the fabric can be accomplished in any suitable manner as by a tentering machine of any usual construction in which the fabric is held out to its full width by traveling clips or the equivalent which grip each selvage and carry the fabric through a steam heated chamber.

The rosin soap and glycerin are taken up by the individual yarns and are contained mainly in the yarns rather than between them or in the interstices of the weave. While the proportions of rosin soap and glycerin can be varied from the proportions given tests have indicated that the proportions given result in a more durable and better wearing wheel. The rosin soap enters the individual yarns of the fabric and strengthens them so thatthe fibres when they become detached from the fabric leave the fabric in small dust-like particles, which is desirable, and not in long lengths or ravelings. The rosin soap also has a relatively high melting point and so withstands the heat developed by the bufling operation and therefore does not melt and be thrown off the wheel by the centrifugal force developed at its high rotative speed. The glycerin is absorbed by the fibres. It is hygroscopic and absorbs moisturefrom the atmosphere which moisture enters and thus strengthens the cotton fibres and renders them more flexible, moist cotton fibre being. stronger than the dry fibre, that is, stronger in resisting the wear of the buffing operation. Glycerin also helps prevent the charring of the fabric by raising the moisture content of the cloth. The rosin soap and the glycerin mutually improve each other; for example, rosin alone or its compounds are too dry and hard and tend to dust ofl on the polished bufled surfaces, whereas glycerin alone tends to' give too soft and raggy a finish. The bufilng action of the cloth is the result of a constant whipping action and the ideal cloth must be strong, tough and resilient. Tests have indicated that the fabric treated with the combination of rosin soap and glycerin is much superior to fabric treated with either material alone although fabric treated with either material shows a material advantage in reduced wear over the same but untreated fabric. The fabric is preferably a cotton fabric of balanced weave, that is, containing approximately an equal number of warp and weft strands per unit length with both sets of strands having the same or approximately the same count and twist of yarn. A fabric of unbalanced weave can be used, however, and the wearing qualities thereof are greatly improved by my invention. The polishing compound, usually tripoli in a wax stick, is applied to the periphery of the wheel by pressing the stick against the rotating wheel, the compound being picked up by the fabric discs. In the usual bufling wheel the compound usually remains near the peripheral portion of the wheel. With the wheel of the present invention, however, the polishing compound works a much greater distance toward the center of the wheel which is desirable in that the compound adheres to the wheel better and less polishing compound has to be employed.

Tests on bumng wheels employing treated and untreated fabrics of the same character have shown a marked advantage for the treated fabric. With an 80 x 80 untreated fabric of 3.49 yards per pound, 34.8 pieces were buffed per ounce of cloth and '7 pieces were buffed per ounce of tripoli. With the same fabric treated as above described 57.3 pieces were buffed per ounce of cloth and 7.3 pieces were buffed per ounce of tripoli, thus indicating a marked economy of operation. Tests on other fabrics disclose corresponding savings.

I claim:

1. A bumng wheel comprising a plurality of fabric layers treated with rosin soap and glycerin.

2. The process of making a fabric for bufiing wheels which comprises treating the fabric with a. water solution of rosin soap and glycerin until the fabric is approximately saturated with the solution and then removing excess solution and A drying thfi fabric.

- KENNETH HOMES BARNARD. 

